Indexed by Yahoo and Bing, not seen by Google

Hello Nicu,
Yes your site isn’t yet indexed by google.
Go to Dashboard-> Settings-> Reading -> Search Engine Visibility
Uncheck Discourage search engines from indexing this site
Click Save changes.
Check to see if your site can be found by Google. If not, go through the article for complete settings of the Yoast Seo.
https://www.wpbeginner.com/plugins/how-to-install-and-setup-wordpress-seo-plugin-by-yoast/
If still your site isn’t found may be your site is penalized by Google thats why it is not showing up in Google anywhere. Please work on quality guidelines suggested by Google and remove the duplicate content and the links. Also, please go through the quality guidelines of google and make the website fresh and quality based.See https://support.google.com/webmasters/answer/35769?hl=en

Thank you!

Check this also:
https://www.2createawebsite.com/traffic/search-engine-traffic.html

Thank you, Madhusudan Pokharel

Sudenly, Google indexed my site and now it is on 3-4-5 position. Referring the unchecked box of “discourage….” it was allready unchacked, since Yahoo and Bing found it quickly.
Still, from two days it does not show my new posts (neither in Google, nor in Yahoo).
I will read the links you gave me for setting up YOAST.
I also think that it is a problem with my new server provider. I have another site on another server and it shows my modified posts or pages absolutely intstantly (www.brusselimpex.ro), no matter the browser.
Thank you again.

You are welcome Nicu.Yoast is very good option to try.